RAINN is typically a good resource, getting much of their data from the DOJ, but I don't know why numbers would have fallen that much since the 90s.
While there is certainly some social stigma against rape, there's also a lot of social support for the traits of masculinity in this culture that often lead to it. These include the belief that women exist to be sexually pleasing to men, and also that men have the right to control women. One research study I saw from a few years back the interviewer asked college guys if they had ever coerced a woman into doing something sexual that she didn't want to do. 25% of them admitted to doing that, which means that the actual number is undoubtedly much higher. Coercion like that is a form of rape - our culture just has a longstanding practice of teaching boys they should press, and press, and cajole, and pressure until they get what they want - no matter what she wants. These college boys had all grown up on consent conversations but they still didn't really see that what they were doing was wrong.
"The average age of women who experienced forced sexual initiation was 15.6. The average age of the partner or assailant at the time was 6 years older. Among women whose first sexual intercourse was voluntary, the average age was 17.4.Some 50% of women surveyed said the perpetrator was larger or older. More than 46% of the women were held down. In 56% of the instances, men used verbal pressure. Men used physical threats more than 26% of the time and caused physical harm in more than 25% of the instances. Some 22% of the women were drugged.”(emphasis mine) CNN Health"
We've got to unhook masculinity from domination if we're ever going to have a better culture, on this front, but just in general.
